Identification vs. Verification There are two primary functions offered by any biometric system. One is identification, a one-to-many (1:M) matching process wherein a biometric sample is compared to a set of stored samples in a database. The other is verification, a one-to-one (1:1) matching process in which the biometric system compares an individual's biometric sample to previously enrolled data for that user. The process of verification narrows the biometric database search by including other identifiers such as names or IDs. The terms "verification" and "authentication" are sometimes used interchangeably because both terms are used primarily to establish a specific user's validity rather than to identify users by querying an entire database of biometric samples.

Authentication Any systematic method of confirming the identity of an individual. Some methods are more secure than others. Simple authentication methods include user name and password, while more secure methods include token-based one-time passwords. The most secure authentication methods include layered "multimodal" biometric procedures. This is independent of authorization.

FAR and FRR Most modern biometric security systems can be fine-tuned to fit the needs of either high security or low security environments. Increasing security in biometric systems sometimes makes them more finicky, resulting in an increased False Rejection Rate (FRR) - this is manifested when a registered user's biometric data (e.g. fingerprint minutiae data) is rejected by the system. In these cases, emphasis on ambient lighting, climate, or user training may be needed. The net effect of FRR is usually nothing more than inconvenience to users. However, if security is set too low, the False Acceptance Rate (FAR) may increase. This is potentially far more serious, since it involves an unauthorized person gaining access to protected resources. The FAR and FRR varies widely between biometric systems.

The attendance system has a Scanner attached to a computer in which Finger prints of all the enroll employees are stored whenever a employee comes he put is finger on the scanner and system marks his time ( in- out as specified ) automatically . There can not be any proxy attendances.